A very similar question was asked here:
http://www.usingenglish.com/forum/as...tml#post229709. There are a couple of interesting links in my answer(s? - I forget). But it is unrealistic to think 'I must learn tens [or even hundreds] of thousands of words before I can be called fluent'. If you can communicate efficiently about the things you need to communicate about, fluency will come. You don't need to learn lists.
b